Food residue is often found coating the inside of microwave ovens, especially industrial, commercial and educational settings. Over time, the accumulation of the food produces an unsightly mess that is also difficult to clean, as the material is repeatedly dehydrated to aggressively adhere to the surface. Attempts to scrub away the particulate by conventional method (i.e. abrasive sponge with soap and water) are time-consuming and may damage the plastic walls of the microwave. The process is also difficult because the worse part of the mess is often on the top of the oven, the area that is the hardest to see and clean. While microwave ovens have become symbolic of being quick and easy to use, the same is not true of cleaning them.
This problem has been noticed and several patents have been issued applying alternative solutions.